<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*div {*/
        /*    width:50px;*/
        /*    background: orange;*/
        /*}*/
        .abc{
            width: 200px;
            height: 200px;
            background: orangered;
        }
        .bbb{
            width: 100px;
            height: 100px;
            background:yellowgreen;
        }
    </style>
</head>
<body>
<div class="abc">first</div>
<div class="abc">second</div>
<div class="bbb">third</div>
</body>
</html>